Imaging used to read ancient scrolls 'carbonized' by Vesuvius

Researchers using a 3-D X-ray imaging technique called X-ray phase contrast tomography (XCPT) have been able to read ancient Roman scrolls that were burned during the eruption of Mount Vesuvius in 79 A.D.

According to an article on discovery.com, the scrolls in question were two of the 1,785 scrolls excavated 260 years ago from a villa in Herculaneum that housed what was considered to be one of the finest libraries in antiquity. The scrolls are now stored at the National Library of Napes and are believed to hold works such as Aristotle's lost 30 dialogues, philosophical work by Epicurus, erotic poems by Philodemus, Virgilius's lost eclogue, scientific work by Archimedes and lesbian poetry by Sappho.

The problem with most of the the scrolls is that they were carbonized, making them extremely fragile and likely to be damaged if any attempt was made to unroll them. At the same time, said Vito Mocella, a physicist from the National Research Council’s Institute for Microelectronics and Microsystems in Naples, “imaging techniques have been unable to view the carbon-based ink of these papyri, even when they could penetrate the different layers of their spiral structure.”

According to Mocella and colleagues, who reported on the ability to read the scrolls with XCPT in an article in the journal Nature Communications, ancient papyri were written using a black carbon-based ink, the density of which is the same as that of carbonized papyri. Consequently, conventional X-ray techniques couldn’t distinguish the ink from the papyrus inside the carbonized scroll.

But, XCPT can take advantage of some of the subtle differences in the way X-rays pass through ink and papyrus, making it possible to read some letters.

Mocella and his colleagues used the technology at the European Synchrotron Radiation Facility in Grenoble, France to examine two scrolls—one unrolled and one rolled—that had been given to Napoleon Bonaparte as a gift and now reside in the collection of the Institute de France.

Even though the layers of the rolled up scroll had been folded in a “nearly chaotic and badly entangled fashion,” Mocella and colleagues wrote in Nature Communications, the researchers were still able to pick out all 24 letters of the Greek alphabet, identify several words as well as a specific writing style most likely that of the Greek philosopher and poet Philodemus.

“Here for the first time, we show that X-ray phase-contrast tomography can reveal various letters hidden inside the precious papyri without unrolling them,” they wrote. “This attempt opens up new opportunities to read many Herculaneum papyri, which are still rolled up, thus enhancing our knowledge of ancient Greek literature and philosophy.